Heated Handgrips for Concours

Warning

I am not a mechanic or a representative of any motorcycle or tool manufacturer or anything else official. This page is only my notes on doing this procedure myself. Although I believe what I have documented here is correct, I make no promises and you do this at your own risk.

It’s usually uncomfortably cold here for a month or two before there is a permanent snow cover, so heated accessories can extend the riding season by several weeks. I use an Aerostich heated vest, and heated handgrips. This page shows the installation of the heated grips.

I bought HotGrips heated grips for the Concours. These are available direct from the manufacturer, but I bought mine from Aerostich Rider Wearhouse, as their prices were better and they’ve always been a pleasure to deal with. I received the grips by courier two days after placing the order. The grips for the Concours are 4.75″ by 7/8″, Hotgrips part number 475-875. Since the Concours has bar-end weights, you must also ask for the free option of having the outboard ends bored out.

I didn’t order the optional variable heat controller, so the grips come with a simple two-way switch, the two sides of which are to be wired direct or through a heavy power resistor to give “full” and “half-intensity” heat options.

Mechanically, mounting the grips is simple. The electric wiring was more work. I wanted the grips switched, with a pilot light, and wanted them driven by a source that was not on when the ignition was off. (I wasn’t worried about forgetting to turn them off so much as about passers-by flicking the switch and draining the battery.) I ended up mounting an automotive relay under the seat, switched by power from the running lights, and having the relay switch the high-current line from the accessory lead for the grips. To get the setup I wanted, I didn’t use the switch (a single-pole, double-throw, centre-off toggle) that came with the grips. Instead, I bought a DPDTCO (Double-pole, double-throw, centre-off) and used this wiring setup. This made it easier to wire the pilot lamp.

I removed each with a hex key. They were secured with Loc-Tite, so it required quite a bit of pressure.

Here’s the bar with the weight removed. Now, I had to get the old grip off. For some reason, I had it in my head that I should get them off in one piece.

I thought I would be able to roll the rubber grip back, turning it inside out. Although it was willing to start, it was much harder than I expected.

I tried warming the grips with a heat gun to soften them, to see if that made it any easier to roll them back.

It didn’t. I was able to get it back another 1/2″ or so. Then I realized, “why am I trying to get it off in one piece? It’s not going to be reusable anyway, because the new grips are epoxied on.”

So I stopped trying to be elegant, and slit the rubber with a sharp knife.

Then the old grip easily came off of the metal handle bar.

As recommended by the instructions, I then test-fitted the new grip, and lightly sanded some residual adhesive so that it slid on easily.

It fit snugly and the length looked good.

Next I cut the grip off the throttle side and, again, test fitted the replacement grip. The replacement grip for the throttle side has a bigger hole through it, to accommodate the throttle tube.

Next I tested the rotation of the throttle, finding a position for the electric wire where it was out of the way but did not bind on the front brake lever when the throttle was rotated all the way open.

Next I sanded the throttle tube with coarse emery paper, leaving lots of scratches, so the epoxy would have a good surface to which to adhere.

The instructions recommend a standard 8-hour epoxy, not the 5-minute stuff, since the longer-setting material is more heat resistant.

They also specify coating the entire handlebar tube, so I mixed up quite a lot — about half a tube.

I held a scrap of cardboard under the handle while working to keep any drips off the bike,

and spread epoxy until the entire throttle tube was evenly covered. As instructed, I was very careful to keep the epoxy away from the tube ends so it didn’t creep into the moving parts of the throttle mechanism.

When fitting the grip on over the glue, I was careful to line the wire up with the previously-determined position where the throttle motion doesn’t interfere with the controls.

The clutch side was a repeat of the same process. First, I roughened the bar with coarse emery paper,

applied an even coat of epoxy over the whole surface,

and slide the grip on, with the wire lined up at the bottom rear where it’s not in the way.

It was cool in the day and cooler at night when I did this, so I left everything undisturbed for 24 hours for the epoxy to cure properly.

While the epoxy was hardening was a good time to experiment with some wiring options, testing the operation of a relay, the grip’s power resistor, indicator lamps, and so on.

I wanted to wire a switch into that nice clear space on the panel (circled in green here), so I removed the left “middle fairing” to make access easier.

Note the location of handy fused accessory leads (green), and a structural frame tube (pink), suitable for mounting the power resistor (the instructions recommend mounting it on a metal part to act as a heat sink).

I used a volt meter to identify the polarity of the accessory leads, and marked them.

Then, I disconnected the left-side running light and used a meter to determine which lead was a 12V supply switched by the ignition key.

I carefully bared a length of this switched power line and wound on another wire,

then carefully soldered this connection, and re-insulated it with electrical tape, giving me a switched low-current 12V line. (Enough current to run a relay, but not enough to run the grips.)

Next I wanted to mount the switch and indicator light. At first I had two lights in mind, but later went to a single light to simplify wiring.

I marked a suitable spot for the switch, feeling under the dash to make sure the space there was clear too.

Then I drilled the appropriate holes for the switch and two indicator lights.

(Later, I plugged the bottom hole and used only the top indicator light. )

To run the grips, I bought a 12V auto relay. It draws only about 80 ma to operate, and can switch a 10 amp circuit.

I used one of the mounting bolts for the battery tray, under the seat, to hold the relay in a convenient and weather-shielded location.

Then I wired the circuit between switch, light, relay, and grips. Here is the ground lug of the relay, being connected to the ground terminal of the under-seat set of accessory leads.

To get the control signal and power to the front of the bike, I removed the rear gas tank mounting bolts, lifted the tank slightly, and ran a few wires under the tank.

Here is the wired relay, showing the control circuits and switched power circuits connected.

At the front of the bike, all the wiring is twisted and soldered, using a scrap of wood as a support for the soldering operation.

Every joint is finished with a bit of heat-shrink tubing (which I constantly forgot to put over the wires before soldering). A garden tool behind the wire kept the heat from softening other wires.

Here is the wired switch and lamp,

and the under-dash wiring to the resistor and the power leads from the grips.

As recommended by the manufacturer, the power resistor is sitting on a bed of silicone sealant, firmly held to a steel frame tube with cable ties. This provides sturdy support and allows the frame to conduct heat away from the resistor when the system is running in half-power mode (at which time the resistor gets quite warm).

I replaced the middle fairing, and tidied up. Here is the finished grip, throttle-side.

And, with all the fairings replaced, the switch fits neatly into the dashboard layout.